Universally adored Aussie icon Olivia Newton-John has been forced to postpone a number of her US and Canadian tour dates following the very sad news that her breast cancer has returned.

In a statement via her official Facebook page today, a rep for the veteran pop darling announced the worrisome diagnosis, revealing that the disease has spread to her spine.

“The back pain that initially caused her to postpone the first half of her concert tour, has turned out to be breast cancer that has metastasized to the sacrum,” the statement reads.

“In addition to natural wellness therapies, Olivia will complete a short course of photon radiation therapy and is confident she will be back later in the year, better than ever, to celebrate her shows.”

The 68-year-old Grease star was previously diagnosed with the disease 25 years ago but was eventually given the all clear and became a became a vocal campaigner for other cancer-sufferers.

She set up the Olivia Newton-John Cancer and Wellness research centre in Melbourne, where she’s been consultating with doctors about her new treatment options.